Optimal RAID question?

[A_Reed048]

I’m planning out a PC build for the near future and while I am building up a bank roll I am trying to educate myself of all the ins and outs of more modern builds ( I haven’t built my own computer in about a decade). I have an idea of what I am shooting for with the rest of the components but I am confused with all of the options available with storage.

I was thinking about having anywhere between 4-8 drives in my system, possible combination of SSD and HDD. I want some kind of data redundancy built in regardless of what I do so I was going to shoot for RAID 5,6 or 10. I guess the question here is what combination is going to give me a good balance of performance, reliability and capacity? Do SSDs make sense in these standard RAID configurations? I’ve heard about smart caching to SSD but what does that entail in setup, do I RAID the mass storage together and have the system cache to the SSD(s) or what?

I know that if I build around a RAID 5/6 type setup the more drives the merrier as far as capacity efficiency is concerned but this setup also ventures into the realm of needing a dedicated RAID card, something I’m not 100% on buying at this time. I’ve also heard these configurations are only as fast as the slowest drive in them; wouldn’t putting an SSD in the array be a waste?

If I build around a RAID 10 I lose half my capacity but keep a much simpler RAID structure that probably won’t require a dedicated card. Again do SSDs have a benefit here either?

It is in my nature to find an optimal solution but I’m stuck when I don’t know how the entire system works.

[Vitalius]

RAID 5/6 is the best Redundancy to Storage space ratio while sacrificing a bit of Performance. 

RAID 10 is the best Redundancy to Performance ratio while sacrificing a bit of Storage space

SSDs should probably only be used in RAID 1 at most. 0 is unnecessary, 10 is unnecessary, and 5/6 doesn't make sense to me. Using them for cache for a RAID 5/6 might be good to offset the performance loss (it's minimal anyway though).

SSDs should only be as cache. Unless it's a pure SSD RAID array, never put an SSD in a RAID array.

If you do use RAID 5/6, you are limiting yourself to slightly more expensive drives (WD Reds, SE, or RE and Seagate NAS drives as examples). They will give better performance though, run cooler, and prevent the RAID from being lost easier in the future.

I would go with RAID 10 personally. It just makes the most sense to me in terms of simplicity and redundancy at the cost of more storage space.

[Toxic Tom]

If you did an 8 drive RAID 10 with hard drives you would get redundancy, speed and capacity.

 

No need for SSDs!

[ShadowCaptain]

I run raid 10 in both my server and home system

 

It is the most expensive, but also the fastest and with the most redundancy as it can sustain 2 drive failures and still function, while still giving  the performance boost of raid 0

[SMURG]

I'm not a huge fan of SSDs. I used them in my desktop as drives for the OS and games (I bought a 480GB one for games and a 120GB for the OS + a few programs) and honestly I was happier with the RAID 0 I had before. I also have an SSD in my surface pro 2 though, and in that scenario I appreciate the fast boot a lot more.

The other place I use an SSD is in my file server as a write cache. The rest of the drives are in RAID 5 and the write performance of that array is pretty bad. For that reason if you do go with RAID 5/6 but want to retain write speeds, I'd recommend an SSD as write cache. As others have said, RAID 10 (or 0 if you're a balls-to-the-wall kind of guy) HDDs should be enough in terms of speed for your OS and applications.

[Vitalius]

I run raid 10 in both my server and home system

 

It is the most expensive, but also the fastest and with the most redundancy as it can sustain 2 drive failures and still function, while still giving  the performance boost of raid 0

Well, it depends on which two drives fail. If 2 drives on the same RAID 1 fail, then you lose the array. If 1 drive on each RAID 1 fail, you are fine. But it's better than RAID 5, and not as good as RAID 6, but in between the two in terms of redundancy. 

Also, if you have a smart OS, it can read the data off of a RAID 1 array as if it's RAID 0, so RAID 10 is like two RAID 0's for read, but you need something like Linux or FreeBSD ZFS for that.

 

I'm not a huge fan of SSDs. I used them in my desktop as drives for the OS and games (I bought a 480GB one for games and a 120GB for the OS + a few programs) and honestly I was happier with the RAID 0 I had before. I also have an SSD in my surface pro 2 though, and in that scenario I appreciate the fast boot a lot more.

The other place I use an SSD is in my file server as a write cache. The rest of the drives are in RAID 5 and the write performance of that array is pretty bad. For that reason if you do go with RAID 5/6 but want to retain write speeds, I'd recommend an SSD as write cache. As others have said, RAID 10 (or 0 if you're a balls-to-the-wall kind of guy) HDDs should be enough in terms of speed for your OS and applications.

One very important thing to have for an SSD Write Cache is a Battery Backup. If the power goes out while the system is writing, it can corrupt your files, and if you have your OS on the RAID, that can corrupt the whole OS.

So SSD write caches need some form of power backup to be reliable.